The present invention relates generally to a method and apparatus for cleaning and sterilizing rotary backpressure filling machines. The filling machines comprise filling elements and pressure actuated conveyor means which operate to support the vessels during the machine operation. More particularly, invention relates to a method and apparatus for effecting a cleansing operation by attachment of a rinsing vessel to the filling machine by operation of the pressure actuated conveyor means, with a cleansing operation occurring during the time that the rinsing vessel is in the attached condition and with the rinsing vessel being automatically detached by operation of the filling machine after cleaning.
In apparatus of the type to which the present invention relates, the filling of beverages requires absolute cleanliness in the portions of the filling machine within which the liquid beverage is carried. For this reason, the liquid carrying parts of a rotary bottle filling machine must be cleaned and sterilized at regular intervals. In such an operation, all the parts of the filling element of the machine which are arranged exteriorly of the liquid tank must also be exposed to the cleaning fluid.
In accordance with a known art method for cleaning such filling machines, the filler tank of the machine is connected through the liquid feed pipe to a filler feed pump by means of which the tank may be filled completely with cleaning fluid. During a subsequent slow rotation of the machine, all filling and relief valves are open so that fluid flow may be established as a result of the overpressure of the pump of the machine through the fluid outlet duct. Additionally, partial fluid flow is established through the relief valve of the machine. The cleaning fluid is collected in a ring conduit and is fed once again to the feed pump. However, in this known measure unsatisfactory results are attained because this approach is incapable of achieving the desired level of microbiological cleanliness required in the filling machine. This is particularly true since the relatively narrow relief ducts, as well as the parts of the air pipe leading to the exterior of the machine together with the centering device of the machine cannot be sufficiently exposed to the cleaning fluid due to pressure drop at the level of the fluid outlet pipe connection.
It has therefore been proposed to clamp a rinsing vessel to the machine which encloses the return air pipe between the vessel centering bell arranged at its bottom position and the press fit of the filling element. Such a rinsing vessel bears upon the centering bell holder and, to this end, the bell is removed from the holder and cleaned by hand outside the filling machine.
Since such a rinsing vessel consists of a closed housing upon which there is guided a supporting ring, the supporting ring rests on a centering lug of the centering bell holder and presses the rinsing vessel housing under a spring force against the press fit of the filling element. In this known design, the rinsing pressure acting within the vessel is absorbed by the pressure spring. In order to permit easy handling of the rinsing device, only a relatively low surface pressure may be effected. Consequently, the counteracting rinsing pressure is also limited. This results in an additional disadvantage in that the relatively narrow ducts provided for antechamber air and relief of the vessel interior of the rinsing fluid are not sufficiently reached because of the low rinsing pressure. Furthermore, it becomes impossible to circulate the rinsing fluid with a cleaning fluid at the inner surfaces of the centering bell which is disassembled in this case. This known approach will not permit operation beyond such automatic cleaning as it also requires automatic closure of the filling element after a relatively short preparation time, since all the rinsing vessels must be inserted by hand thereby requiring considerable time particularly in view of present day heavy duty machines which frequently involve up to 164 filling stations. SUMMARY OF THE INVENTION
The present invention is aimed at alleviating problems and disadvantages involved in methods of the type previously described by providing a method and apparatus wherein all processes occur substantially automatically and wherein a maximum degree of safety is ensured for the cleaning of the filling machine with cleaning of all fluid-carrying parts being achieved. The problems are solved according to the present invention in that after a rinsing vessel has been introduced, it is raised toward the centering element of the machine and it is placed under pressure in this state so that it is fastened on the filling element with the fastening being effected automatically and with continued pressure increase, for example, when pressure equalization has been achieved between the interior of the rinsing vessel and the filling machine tank, initiating operation of the rinsing process by opening the fluid valve. Rinsing is limited to spaces and openings below the valve seat, and after lowering of pressure actuated conveyor means of the machine and with resulting closing of the fluid valve, while maintaining rinsing pressure, and with continued rotation of the filling machine, the process is started once again by applying the pressure actuated conveyor means against the rinsing vessel with pressure being applied thereto.
The measures of the present invention fully meet the requirements discussed above and give rise to an advantage in that the rinsing operation is not interrupted during the forced lowering of the lifting or pressure actuated conveyor means at the level of the outflow star and the subsequent lifting behind the inflow star. Rather, it becomes possible to direct the rinsing accurately to the lower regions of the filling element below the fluid valve and the return gas pipe. After the passage through the outflow and inflow regions of the machine, the main rinsing process is started again by lifting the pressure actuated conveyor means with resulting opening of the fluid valve after pressure equalization occurs.
In a further aspect of the present invention, the rinsing vessel is locked by pressing against parts of the filling element and subsequent admission to its interior of rinsing pressure and is removed from the filling machine by relieving the interior pressure and subsequently lowering the pressure actuated conveyor means.
In an additional aspect of the invention, the use of a rinsing vessel held by pressure admission on parts of the filling element is involved.
A device suitable for carrying out the method according to the invention for an arrangement for cleaning and sterilizing rotary backpressure filling machines for cleaning filling elements with a rinsing vessel is characterized by the fact that the rinsing vessel includes a fastening mechanism which is actuated during axial movement of a part of the vessel.
A particularly expedient design of a device for carrying out the method of the invention is characterized by the fact that the rinsing vessel consists of housing parts which are telescopically movable against spring pressure, with one of the housing parts being designed as a sliding sleeve which is operatively associated with clamping means which are actuated by movement thereof in a direction extending radially of the axis of the housing. In accordance with the invention, the fastening mechanism is adapted to engage the air and/or filling pipe of the filling machine.
In the construction of the rinsing vessel, a cylindrical inner member is provided and a sleeve is arranged to be slidably movable relative thereto, with an additional part being provided which is movable relative to the sliding sleeve. Radially acting clamping means are also provided which engage the filler pipe of the filling machine. The radially acting clamping means have their radial range of motion limited by a recess formed in the sliding sleeve which determines the outermost position of the clamping means. The innermost position of the clamping means is limited by a conically tapered surface formed on the sliding sleeve.
It has been found expedient to form the sliding sleeve in a divided configuration and to arrange in engagement therewith a supporting ring which is displaceable relative to the sleeve in a radial direction.
In the operation of the invention, the rinsing vessels are placed on the feeder element of the machine directly before the start of the cleaning operation of the filling machine, and the rinsing vessel is brought to a desired distance from the dividing screw. As soon as a rinsing vessel is engaged by a standing platform of the pressure actuated conveyor means, the platform rises in a known manner toward the filling element of the machine and presses a sealing element against the filling element thereby entraining the centering element. Immediately thereafter, backpressure is produced by opening the antechamber air duct of the machine so that the axis movement of an inner vessel part is commenced and so that the fastening mechanism is thus moved toward the fill pipe of the machine. With continued admission of pressure to the interior, the pressure between the rinsing vessel and the filling machine tank becomes equalized after a short period of time. Thus, the fluid valve opens automatically and the rinsing fluid begins to circulate, with the vacuum valve being open. During this process, all fluid carrying parts are satisfactorily reached by the cleaning fluid. With continued rotation of the filling machine, a position is finally reached where the lifting elements are forceably moved downwardly. At this moment, an outside relief of the rinsing vessel sets in, so that the inner part provided with the clamping means is moved downwardly by the internally acting pressure applied to it and by a compression spring thereby closing the fluid valve. At this moment, the rinsing is directed accurately through the return gas pipe to the parts of the filling element arranged therebelow.